Firearm butt plate with liquid recoil absorbing device



Sept. 26, 1961 c. s. CAMPBELL 3,001,312

FIREARM BUTT PLATE WITH LIQUID RECOIL ABSORBING DEVICE Filed March 24,1958 2 Sheets-Sheet 1 INVENT OR. CLARK S. CAMPBELL P 1961 c. s. CAMPBELL3,001,312

FIREARM BUTT PLATE WITH LIQUID RECOIL ABSORBING DEVICE I Filed March 24,1958 2 Sheets-Sheet 2 INVENTOR. CLARK S.CAMPBELL BY 62,, TZZ$W UnitedStates Patent 3,001,312 FIREARM BUTT PLATE WITH LIQUID RECOIL ABSORBINGDEVICE Clark S. Campbell, Ilion, N.Y., assignor to Remington ArmsCompany, Inc., Bridgeport, Conn., a corporation of Delaware Filed Mar.24, 1958, Ser. No. 723,225 3 Claims. (Cl. 42-74) This invention relatesto firearms and more particularly to a device for cushioning the forcesof recoil at the time of firing so that the reaction of the firearmagainst the body of the operator is spread over a given period of timerather than allowed to act directly and more or less instantaneously.

The trend to lighter weight firearms of increased power means thatgreater recoil energies and higher recoil velocities are developed. Withheavier weapons or ones with less power recoil energy has been less andthe lesser recoil velocities have tended to spread the application ofthe recoil forces to the shooters body over a longer period of time,avoiding the painful and harmful short duration forces of greatmagnitude which characterize the lighter and more powerful arms.

Devices have been tried in the past which were intended to cushion theshock of recoil. However, these have not been satisfactory in operationor practical to manufacture due to complexity of fabrication, difiicultyof assembly and disassembly, inefficiency and other defects.

It is an object of this invention to provide an improved and practicalshock absorption mechanism capable of being produced economically, andefiicient in cushioning recoil forces of large magnitudes.

It is a further object of this invention to provide an proved hydraulicrecoil absorbing device which does not require the usual partsmanufactured to close tolerance, or expensive complex sealingarrangements.

It is a further object of this invention to provide an improved recoilabsorbing device which will function uniformly and satisfactorily forvarying points of application of the shooters shoulder to the butt ofthe gunstock without binding or jamming of the mechanism.

Other objects and advantages will be apparent from the followingdescription of the invention taken in conjunction with the accompanyingdrawings wherein:

FIGURE 1 is a partial side view of a firearm stock embodying thefeatures of my invention showing the general arrangement and appearance.

FIGURE 2 is an enlarged side view of the firearm stock of FIGURE 1 withthe flexible cover removed to show the arrangement of the mechanismparts.

FIGURE 3 is a vertical transverse section of the device of FIGURE 2taken at line 3-3.

FIGURE 4 is a vertical longitudinal section of the recoil absorbingmechanism to show more clearly the inner portions and components.

Generally, the forces of recoil are regulated by hydraulic liquid flowthrough a throttling orifice in cooperation with a unique mechanism forinsuring that the major parts between which the relative movement takesplace are always in proper alignment for uniform movement free ofbinding or jamming due to varying points of application of the shootersshoulder resistance against the butt.

Looking at FIGURE 2, the gun stock 2 of a firearm is provided with asection 6 of reduced transverse dimensions and a bore 4 positionedlongitudinally therein. Secured to the rear end of stock 2 by screws orbolts 18 is a member 17 having a passageway therethrough in alignmentwith bore 4 of the stock. Member 17 is formed 3,001,312 Patented Sept.26, 1961 with two rearwardly projecting lugs 41 and 42. Member 17carries two transverse pivot shafts 11 and 12 therein. Pivotally mountedon shafts 11 and 12 are rocker levers 14 and '15 respectively which areinterconnected by meshed gear tooth portions at 16. The interconnectedportions at 16 normally rest in abutting relationship against the endsurface of stock 2. Rocker levers 14 and 15 are connected to a buttplatemember 1, which is made of plastic, metal, or other material, by pins 10and 13 respectively. As can be seen from FIGURE 2, this securesbuttplate 1 to the stock 2 in a manner which allows only limited axialmovement therebetween.

Buttplate member 1 is provided with a hollowed out interior portion 39and two forwardly projecting lug elements for limiting movement towardthe stock 2 and in which are mounted the pins 10 and 13.

R-igidly secured in the bore 4 of the stock 2 is a tubular element 7which extends through member 17 toward buttplate member 1 and, inconjunction with projections 41 and 42, supports crosshead element 19against movement toward stock 2. Crosshead element 19 is positionedlaterally by the hollow 39 in the buttplate 1 and is provided with acentral metering or throttling orifice 20. A liquid container 23 offlexible material is provided, having a rearward portion set in thehollowed out interior portion 39 of the buttplate member 1 arranged tobe compressed by crosshead element 19 during firing. The container has anecked down portion 21 extending through the metering or throttlingorifice 20 in element 19 and an enlarged portion connected therewithpositioned in the rearward end of tube 7. A spring biased plunger 9slidably mounted in tube 7 exerts a force rearwardly on the container23. The spring 8 is known as the oil return spring. The rearward innerwall of buttplate member 1 is provided with a throttling projection 22which is aligned with the orifice 20 in the crosshead element 19.

Buttplate member 1 and stock 2 are urged apart to the extent of thelimited axial movement therebetween by two spring-urged plungers 33which together with their preload springs 31 are mounted in axial bores32 in the stock 2.

The flexible container 23 is filled with a suitable hydraulic liquid Fand, in the equilibrium or rest position as shown in FIGURE 2, containsthe major portion of the liquid rearwardly of orifice 21. In mypreferred embodiment, shown, the preload springs 31 each initially exerta force of about 17 pounds to prevent movement of the device from thepressure with which the shooter may pull the gun against his shoulderand to speed repositioning of the device after firing and oil returnspring 8 exerts an initial force of about 3 pounds for satisfactoryoperation.

A flexible resilient sleeve 3 is fitted over the opening between themembers 1 and 2 to provide a pleasing appearance and prevent foreignmatter from entering the mechanism.

In operation, upon firing of the firearm with which the device isassociated, the stock is forced toward the buttplate element 1. Recoilforce is transmitted by tube 7 and projections 41 and 42 to crosshead19, tending to compress the liquid F in container 23. The rocker levers1 4 and 15 commence their pivoting motion as relative motion betweenmembers 1 and 2 commences. The liquid F is then forced forwardly throughorifice 21 into the portion of container 23 lying in tube 7, loadingspring 8. Springs 31 are also put under further compression. Ascrosshead element 19 moves rearwardly relative to buttplate element 1,the throttling projection 22 moves into orifice 21. The shape of thethrottling projection is such as to reduce the effective area of theorifice 21 the desired amount at every instant so as to retard therelative movement of stock 2 with respect to buttplate 3 element 1 withthe force desired for that instant. After the recoil forces havedissipated, the springs 8 and 31 return the parts to the initialposition and cause the liquid F to return to its rest position betweenthe buttplate element 1 and crosshead element 19.

The point of application of shoulder resistance to recoil forces varieswith the individual shooter from place to place between points indicatedat A and B. It will appear that if the shoulder resistance is applied ator near point A or B there is a tendency to cock or tilt buttplateelement 1 with respect to the remainder of the structure. This wouldcause misaligment and jamming during the relative movement between parts1 and 2 were it not for rocker levers 14 and 15 which provide a forceequalizing linkage to maintain the parts in alignment for free movement.

Thus I have provided a highly effective and practical hydraulic recoildistributing device which is simple to assemble, maintain and replace ifnecessary; needing no costly seals or parts which must be manufacturedto close tolerances as in most hydraulic devices.

It will be obvious to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof and therefore the in vention is not limited to the preferredembodiment which has been disclosed but only as indicated in theaccompanying claims:

I claim:

1. A shock-absorbing device for a firearm comprising in combination afirst member adapted to be secured to a firearm, a second member alignedwith said first member and attached thereto for limited movement withrespect to said first member in the general line of recoil between anextended and a retracted position, a flexible container having a firstportion and a second portion separated by an abutment and having arestricted passageway connecting said first and said second portions, aliquid in said flexible container, said passageway positioned to controlflow of the liquid in the container and to brake relative movementbetween said first and second members, resilient means urging saidsecond member toward the extended position, and means cooperating withsaid first and second members to maintain the alignment thereof.

2. A firearm comprising in combination a buttstock, a movable buttplatemember aligned therewith and attached thereto for limited displacementin the general line of recoil with respect thereto between an extendedand retracted position, aligning means engaging said buttstock andbuttplate member to maintain the relative attitude of said buttstock andbuttplate member unchanged during the relative displacementtherebetween, a shockabsorbing mechanism mounted between said buttstockand said movable buttplate member, said shock-absorbing mechanismcomprising a flexible container having a first portion and a secondportion separated by an abutment and having a restricted passagewayconnecting said first and second portions, a liquid in said flexiblecontainer, said abutment operative upon relative movement between saidbuttstock and said buttplate member to force liquid from one portion ofthe container to the other through said restricted passageway to brakesuch relative movement, means cooperating with said container to varythe rate of How of the liquid through said restricted passageway to varysaid braking action.

3. A shock-absorbing device for a firearm comprising in combination afirst member adapted to be secured to a firearm, a second member alignedwith said first member and attached thereto for limited movement withrespect to said first member in the general line of recoil between anextended and a retracted position, a flexible container holding aliquid, having a first portion and a second portion separated by anabutment and having a restricted passageway connecting said first andsaid second portions to control flow of the liquid in the container andto brake relative movement between said first and second members,resilient means urging said second member toward the extended position,and means cooperating with said first and second members to maintain thealignment thereof, said last-mentioned means comprising aforce-equalizing linkage, said linkage having first and second levershaving a first end connected to one of said members and having a portionnear said second end in abutting engagement with said other member, saidlevers having interconnecting means positioned on said second endsthereof.

References Cited in the file of this patent UNITED STATES PATENTS837,601 Behr Dec. 4, 1906 910,276 Easdale Jan. 19, 1909 1,351,141Thompson Aug. 31, 1920 2,438,142 Brower Mar. 23, 1948 2,731,753 MathieuJan. 24, 1956 2,754,608 Stielfel July 17, 1956

